This issue has been resolved and DNS resolver services have returned to normal.
Posted 24 days ago. May 31, 2018 - 19:33 UTC
We have implemented a fix for this issue and are currently monitoring the results. We will update once we have confirmed it is resolved.
Posted 24 days ago. May 31, 2018 - 18:17 UTC
Cloudflare is currently seeing query timeouts for our IPv4 addresses for our public DNS resolver (22.214.171.124 and 126.96.36.199). IPv6 addresses are currently not affected (2606:4700:4700::1111 and 2606:4700:4700::1001). We are investigating further and will provide updates as they become available.